Successful caudal vena cava and pulmonary vein isolation in healthy horses using 3D electro-anatomical mapping and a contact force-guided ablation system.

BACKGROUND: Recently, treatment of equine atrial tachycardia by three-dimensional electro-anatomical mapping (3D EAM) and radiofrequency catheter ablation (RFCA) has been described. Myocardial sleeves in the caudal vena cava and pulmonary veins are a potential trigger for initiation and perpetuation of atrial tachycardia and atrial fibrillation in the horse. Isolation of these myocardial sleeves by RFCA may be an effective treatment for these arrhythmias. OBJECTIVES: To describe the feasibility of 3D EAM and RFCA to isolate caudal vena cava and pulmonary veins in adult horses using 3D mapping and a contact force (CF)-guided ablation system. STUDY DESIGN: In vivo experiments. METHODS: 3D EAM and RFCA was performed in five horses without cardiovascular disease under general anaesthesia, using the CF-guided system CARTO®3. Point-by-point RFCA aimed for isolation of caudal vena cava and pulmonary veins. Radiofrequency energy was delivered in power-controlled mode with a target power of 45 W, CF between 10 and 15 g and 30 mL/min irrigation rate, until an ablation-index of 450-500 was reached. RESULTS: In the right atrium, myocardial sleeves of the caudal vena cava were isolated (n = 5). In the left atrium, isolation of ostium II (n = 3), ostium III (n = 1) and ostium I, II and III en bloc (n = 1) was performed. Successful isolation was confirmed by entrance and exit block. MAIN LIMITATIONS: Horses were euthanised at the end of the procedure, so long term effects such as potential reconnection of isolated veins could not be studied. CONCLUSIONS: This is the first description of 3D EAM and RFCA with CARTO®3 in horses, thereby showing the technical feasibility and successful caudal vena cava and pulmonary vein isolation. CF measurement allowed monitoring of catheter-tissue contact, resulting in efficient acute lesion creation as confirmed by entrance and exit block. This is a promising treatment for cardiac arrhythmias in horses.

Electrophysiological Response to Acehytisine Was Modulated by Aldosterone in Rats with Aorto-Venocaval Shunts.

Aldosterone induces cardiac electrical and structural remodeling, which leads to the development of heart failure and/or atrial fibrillation (AF). However, it remains unknown whether aldosterone-induced remodeling may modulate the efficacy of anti-AF drugs. In this study, we aimed to jeopardize the structural and functional remodeling by aldosterone in rats with aorto-venocaval shunts (AVS rats) and evaluate the effect of acehytisine in this model. An AVS operation was performed on rats (n = 6, male) and it was accompanied by the intraperitoneal infusion of aldosterone (AVS + Ald) at 2.0 µg/h for 28 d. The cardiopathy was characterized by echocardiography, electrophysiologic and hemodynamic testing, and morphometric examination in comparison with sham-operated rats (n = 3), sham + Ald (n = 6), and AVS (n = 5). Aldosterone accelerated the progression from asymptomatic heart failure to overt heart failure and induced sustained AF resistant to electrical fibrillation in one out of six rats. In addition, it prolonged PR, QT interval and Wenckebach cycle length. Acehytisine failed to suppress AF in the AVS + Ald rats. In conclusion, aldosterone jeopardized electrical remodeling and blunted the electrophysiological response to acehytisine on AF.

Partial Anomalous Pulmonary Venous Connection Repair: Customized Approach and Outcomes.

Alternative options for the correction of partial anomalous pulmonary venous connection (PAPVC) have been proposed. Each can be associated with variable risk for dysrhythmias, caval or pulmonary venous (PV) obstruction. A selective customized strategy to address PAPVC taking into account atrial shunt (AS) and growth potential was pursued. Between September 2014 and August 2018 21 PAPVC patients were identified. Two levels of reference determined the chosen repair strategy; azygous vein (AzV) and cavoatrial junction (CAJ). Six (Group-A) with PAPVC entering SVC cephalad to AV underwent a combined in-situ cavoatrial autologous reconstruction with atrial appendage advancement flap (CARAF). PAPVC entering caudally to AzV (Group-B) underwent alternative repair (caval division/Warden-type or intraatrial rerouting) (n = 15). Age was 8.3 (IQR:4.2-18.5) years for Group-A (vs 11.9; IQR:8.8-34.7 in Group-B) (p = 0.07). In Group-A 5(83%) had AS (vs 12[80%] Group-B; p = 0.9). None had left SVC in Group-A (vs 1 in Group-B; p = 0.9). Preoperative advanced imaging and echocardiographic hemodynamic evaluation was undertaken. Follow-up was complete (median 2.9; IQR:1.2-3.7 years). Freedom from atrial dysrhythmias, caval or PV obstruction was assessed. There were no early or late deaths. ICU and hospital length of stay were 1.8 ± 1.1 and 3.2 ± 0.5 days, respectively. No atrial dysrhythmias occurred postoperatively in Group-A (vs 1 in Group-B; p = 0.9). No permanent pacemaker was implanted. All patients remained in normal sinus rhythm. There were no early or late caval/PV obstruction. A customized approach reserves the advantages of each technique tailored to patient's needs. Expanding surgical capacity with favorable outlook for all PAPVC variations, irrespective of association with AS, can maximize efficiency and reproducibility paired with the lowest morbidity.

Evaluation of a microvascular anastomotic coupler for end-to-side arterial and venous anastomosis for feline renal transplantation.

OBJECTIVE: To describe the technique and determine the feasibility of an end-to-side (ETS) anastomosis of the renal vein to vena cava and renal artery to aorta using a microvascular anastomotic coupler (MAC) for feline renal transplantation. STUDY DESIGN: In vivo experimental study. ANIMALS: Six purpose-bred domestic shorthair cats. METHODS: The left kidney was autotransplanted using a MAC for ETS vascular anastomosis. Outcomes included intraoperative hemorrhage from the anastomosis sites, duration of anastomoses, surgical complications, postoperative renal perfusion (including resistive index (RI)) measured by Doppler ultrasonography and computed tomography angiography, and histopathological examination of the left kidney and anastomosis sites (30 days). RESULTS: Anastomosis was successful in all cats, and intraoperative hemorrhage was negligible. Intraoperative renal perfusion was considered excellent. Venous and arterial anastomoses were completed in 11 minutes 20 seconds (range, 6:38-13:27) and 21 minutes 50 seconds (range, 11:05-30:24), respectively. Vascular occlusion time was 32 minutes (17:43-42:03). One cat was euthanized 5 hours postoperatively because of bleeding from a muscular arterial branch of the dorsal aorta causing hemoabdomen. Renal perfusion and RI of the remaining five cats were within normal range (<0.8) and similar to the contralateral kidney at all time points. Endothelialization of the anastomosis was complete with mild-to-moderate fibrosis surrounding the MAC in all cats. CONCLUSION: End-to-side anastomosis of the renal vein and artery to the vena cava and aorta, respectively, was consistently achieved in all six cats with the MAC. CLINICAL SIGNIFICANCE: The use of the MAC may be considered as an alternative to hand suturing for ETS anastomoses for feline renal transplantation.

Postoperative anemia is a risk factor for acute kidney injury after open aorta and vena cava surgeries.

Open aorta and vena cava surgeries are usually associated with substantial blood loss which may result in postoperative acute kidney injury (AKI). The present study is designed to investigate the prevalence, outcome and risk factors of postoperative AKI associated with open aorta and vena cava surgeries, with a focus on the role of anemia in these conditions. A retrospective review of medical records of Peking Union Medical College Hospital was conducted. Patients who underwent open aorta and vena cava surgeries during January 1, 2010 and June 30, 2014 were included in this study. The primary analysis was between patients underwent open aorta and vena cava surgeryies, with or without postoperative AKI. Multivariable logistic regression models were used to determine risk factors of postoperative AKI. The study included 79 patients (63.3% male) with a mean age of 52.5±17.3 years (range, 17-81 years). Postoperative AKI occurred in 23/79 (29.1%) of the patients. Anemia was present in 11/79 (16%) at baseline, and increased to 45/79 (52%) postoperatively. After adjustment for various risk factors, postoperative anemia (OR, 5.202; 95% CI 1.403-19.285) was independently associated with postoperative AKI. AKI is a common complication in patients who undergo open aorta and vena cava surgeries, and postoperative anemia was the most relevant predictive factor of AKI. Strategies to minimize bleeding and anemia for all patients may be advisable. Further studies are needed to assess the impact of AKI on long term outcome and to examine preventive strategies to address potentially modifiable risk factors.

Mesoportal bypass, interposition graft, and mesocaval shunt: Surgical strategies to overcome superior mesenteric vein involvement in pancreatic cancer.

BACKGROUND: In pancreatic cancer, extensive tumor involvement of the mesenteric venous system poses formidable challenges to operative resection. Such involvement can result from cavernous collateral veins leading to increased intraoperative blood loss or long-segment vascular defects of not only just the superior mesenteric vein but also even jejunal/ileal branches. Strategies to facilitate margin-free resection and safe vascular reconstruction in pancreatic surgery are important, particularly because systemic control of the tumor is improving with multi-agent chemotherapy regimens. METHODS: We describe a systematic, multidisciplinary assessment for patients with pancreatic cancer that involves the superior mesenteric vein, as well as the preoperative planning of those undergoing operative resection. In addition, detailed descriptions of operative approaches and technical strategies, which evolved with increasing experience at a high-volume center, are presented. RESULTS: For the preoperative evaluation of tumor-free, vascular locations for potential reconstruction and collateralization, computed tomographic imaging with high-resolution of vascular structures (used with 3-dimensional or cinematic rendering) allows a precise calibration of radiographic data with intraoperative findings. From an operative perspective, we identified 5 potential strategies to consider for resection: collateral preservation, mesoportal bypass (preresection), mesoportal interposition graft (postresection), mesocaval shunt, and various combinations of these strategies. Many of these techniques use interposition grafts, making it essential to assess autologous veins (preferred conduit for reconstruction) or to prepare cryopreserved vascular allografts (an alternative conduit, which must be thawed and should be matched for size and blood type). CONCLUSION: Herein we share operative strategies to overcome involvement of the superior mesenteric vein in pancreatic cancer. Improvements in preoperative planning and operative technique can address common barriers to resection with curative intent.

The coronary sinus interatrial connection with total unroofing coronary sinus discovered late after correction of secundum atrial septal defect.

A coronary sinus (CS) interatrial connection is a rare congenital anomaly which can be in various types from atrial septal defect type unroofing CS to the total absence of the CS. The pathology usually accompanies the left superior caval vein (LSCV) draining to CS and in case of its absence directly to the left atrium (LA). We present a 53-year-old woman after surgical correction of a secundum atrial septal defect in 1974, with a CS interatrial connection and paroxysmal atrial fibrillation (PAF). She gave a history of PAF and was admitted to our clinic due to progressive exertional intolerance, peripheral edema, and mild hypoxia (SatO2 92%) with subsequent cyanosis. Transthoracic echocardiography showed a left-to-right shunt in the posteroinferior part of the atrial septum. Computed tomography revealed a persistent LSCV draining directly into the LA, the absence of the CS, and cardiac veins draining into the LA. The right atrium (RA) and the LA were connected via a tunnel with a visible contrast passage from the left to the right side-the persisting mouth of the coronary sinus. The patient was qualified for surgical correction. A glutaraldehyde-treated autologous pericardial patch was used to construct the tunnel connecting the LSVC and the RA. The second part of the patch was used to close the atrial communication at the inferior vena cava level. The patient had an uncomplicated postoperative course and is now classified in New York Heart Association Class II.

An in-vitro evaluation of the flow haemodynamic performance of Gore-Tex extracardiac conduits for univentricular circulation.

OBJECTIVE(S): The Fontan procedure is a common palliative intervention for sufferers of single ventricle congenital heart defects that results in an anastomosis of the venous return to the pulmonary arteries called the total cavopulmonary connection (TCPC). In patients with palliated single ventricular heart defects, the Fontan circulation passively directs systemic venous return to the pulmonary circulation in the absence of a functional sub-pulmonary ventricle. Therefore, the Fontan circulation is highly dependent on favourable flow and energetics, and minimal energy loss is of great importance. The majority of in vitro studies, to date, employ a rigid TCPC model. Recently, few studies have incorporated flexible TCPC models, without the inclusion of commercially available conduits used in these surgical scenarios. METHOD: The methodology set out in this study successfully utilizes patient-specific phantoms along with the corresponding flowrate waveforms to characterise the flow haemodynamic performance of extracardiac Gore-Tex conduits. This was achieved by comparing a rigid and flexible TCPC models against a flexible model with an integrated Gore-Tex conduit. RESULTS: The flexible model with the integrated Gore-Tex graft exhibited greater levels of energy losses when compared to the rigid walled model. With this, the flow fields showed greater levels of turbulence in the complaint and Gore-Tex models compared to the rigid model under ultrasound analysis. CONCLUSION: This study shows that vessel compliance along with the incorporation of Gore-Tex extracardiac conduits have significant impact on the flow haemodynamics in a patient-specific surgical scenario.

Pediatric Orthotopic Heart Transplantation.

Since the first pediatric orthotopic heart transplant was performed by Dr Adrian Krantowicz in 1967, just days after the first ever human transplant by Dr Christiaan Barnard, the technique for orthotopic heart transplantation has evolved from biatrial anastomosis to separate caval anastomoses, leaving the right atrium intact. In this video tutorial, we present our technique for standard orthotopic heart transplantation in children.

Predicting the pressure of the total cavopulmonary connection: clinical testing of a mathematical equation.

INTRODUCTION: Some authors advocate the use of a dedicated formula to predict the Fontan pressure starting from pre-Fontan catheterisation data. This paper aims at testing the predictive value of the mentioned formula through a retrospective clinical study. METHODS AND RESULTS: Pre-Fontan catheterisation data and Fontan pressure measured at the completion were retrospectively collected. Pre-Fontan data were used to calculate the predicted pressure in the Fontan system. The predicted values were compared to the Fontan pressure measured at the Fontan completion and with the needs for fenestration. One hundred twenty-four Fontan patients were retrospectively enrolled (At Fontan: median age 30.73 [24.70-37.20] months, median weight 12.00 [10.98-14.15] kg). Fontan conduit was fenestrated in 78 patients. A poor correlation (r2 = 0.05128) between the measured and predicted data for non-fenestrated patients was observed. In the case of Fontan-predicted pressure <17.59 mmHg, the formula identified a good short-term clinical outcome with a sensitivity of 92%. CONCLUSION: The proposed formula showed a poor capability in estimating the actual pressure into the Fontan system and in identifying patients needing fenestration. As the pressure into the Fontan system is determined by multiple factors, the tested formula could be an additional data in a multi-parametric approach.

Norwood Operation With Anterior Translocation of Pulmonary Artery.

Even in the current era of improved clinical outcome of Norwood operation, postoperative pulmonary artery stenosis, recoarctation of the aorta, ventricular dysfunction, and atrioventricular valve regurgitation remain serious clinical concerns. We present 2 cases of successful total cavopulmonary connection after Norwood operation using the right ventricle-to-pulmonary artery shunt with translocation of the pulmonary bifurcation anterior to the reconstructed neoaortic arch. This modification provided a better surgical access to an obstructive pulmonary artery at staged single ventricle strategy and a space for the growth of the pulmonary arteries.

Staged total cavopulmonary connection: serial comparison of intra-atrial lateral tunnel and extracardiac conduit taking account of current surgical adaptations.

OBJECTIVES: Our goals were to compare the outcome of the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC) techniques for staged total cavopulmonary connection (TCPC) and to compare the current modifications of the TCPC technique, i.e. the prosthetic ILT technique with the current ECC technique with a ≥18-mm conduit. METHODS: We included patients who had undergone a staged TCPC between 1988 and 2008. Records were reviewed for patient demographics, operative details and events during follow-up (death, surgical and catheter-based reinterventions and arrhythmias). RESULTS: Of the 208 patients included, 103 had the ILT (51 baffle, 52 prosthetic) technique and 105 had the ECC technique. Median follow-up duration was 13.2 years (interquartile range 9.5-16.3). At 15 years after the TCPC, the overall survival rate was comparable (81% ILT vs 89% ECC; P = 0.12). Freedom from late surgical and catheter-based reintervention was higher for patients who had ILT than for those who had ECC (63% vs 44%; P = 0.016). However, freedom from late arrhythmia was lower for patients who had ILT than for those who had ECC (71% vs 85%, P = 0.034). In a subgroup of patients who had the current TCPC technique, when we compared the use of a prosthetic ILT with ≥18-mm ECC, we found no differences in freedom from late arrhythmias (82% vs 86%, P = 0.64) or in freedom from late reinterventions (70% vs 52%, P = 0.14). CONCLUSIONS: A comparison between the updated prosthetic ILT and current ≥18-mm ECC techniques revealed no differences in late arrhythmia-free survival or late reintervention-free survival. Overall, outcomes after the staged TCPC were relatively good and reinterventions occurred more frequently in the ECC group, whereas late arrhythmias were more common in the ILT group.

Hemodynamic Evaluation of Avalon Elite Bi-Caval Dual Lumen Cannulas and Femoral Arterial Cannulas.

Translational research is a useful tool to provide scientific evidence for cannula selection during extracorporeal life support (ECLS). The objective of this study was to evaluate four Avalon Elite bi-caval dual lumen cannulas and nine femoral arterial cannulas in terms of flow range, circuit pressure, pressure drop, and hemodynamic energy transmission in a simulated adult ECLS model. A veno-venous ECLS circuit was used to evaluate four Avalon Elite bi-caval dual lumen cannulas (20, 23, 27, and 31 Fr), and a veno-arterial ECLS circuit was used to evaluate nine femoral arterial cannulas (15, 17, 19, 21, and 23 Fr). The two circuits included a Rotaflow centrifugal pump, a Quadrox-D adult oxygenator, and 3/8 in ID tubing for arterial and venous lines. The circuits were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 40%). Trials were conducted at rotational speeds from 1000 to 5000 RPM (250 rpm increments) for each Avalon cannula, and at different flow rates (0.5-7 L/min) for each femoral arterial cannula. Real-time pressure and flow data were recorded for analysis. Small caliber cannulas created higher circuit pressures, higher pressure drops and higher M-numbers compared with large ones. The inflow side of Avalon dual lumen cannula had a significantly higher pressure drop than the outflow side (inflow vs. outflow: 20 Fr-100.2 vs. 49.2 mm Hg at 1.1 L/min, 23 Fr-93.7 vs. 41.4 mm Hg at 1.6 L/min, 27 Fr-102.3 vs. 42.8 mm Hg at 2.6 L/min, 31 Fr-98.1 vs. 44.7 mm Hg at 3.8 L/min). There was more hemodynamic energy lost in the veno-arterial ECLS circuit using small cannulas compared to larger ones (17 Fr vs. 19 Fr vs. 21 Fr at 4 L/min-Medtronic: 71.0 vs. 64.8 vs. 60.9%; Maquet: 71.4 vs. 65.6 vs. 62.0%). Medtronic femoral arterial cannulas had lower pressure drops (Medtronic vs. Maquet at 4 L/min: 17 Fr-121.7 vs. 125.0 mm Hg, 19 Fr-71.2 vs. 73.7 mm Hg, 21 Fr-42.9 vs. 47.4 mm Hg) and hemodynamic energy losses (Medtronic vs. Maquet at 4 L/min: 17 Fr-43.6 vs. 44.4%, 19 Fr-31.0 vs. 31.4%, 21 Fr-20.8 vs. 22.4%) at high flow rates when compared with the Maquet cannulae. The results for this study provided valuable hemodynamic characteristics of all evaluated adult cannulas with human blood in order to guide ECLS cannula selection in clinical practice. Use of larger cannulas are suggested for VV- and VA-ECLS.

Transabdominal Intrapericardial Approach in Liver Transplantation for Unresectable Primary Hepatic Functioning Paraganglioma With Invasion Into Hepatic Veins and Suprahepatic Vena Cava: A Surgical and Anesthesia Management Challenge.

Primary hepatic functional paraganglioma is a rare form of extra-adrenal catecholamine-secreting tumor. Definitive treatment of functioning paraganglioma is challenging because of the critical location of the tumor frequently in close proximity to vital structures and risk of excessive catecholamine release during operative manipulation. We report the multidisciplinary management approach for a case of unresectable primary hepatic functional paraganglioma with invasion into the hepatic veins and suprahepatic vena cava. To our knowledge, this is the first report showing that orthotopic liver transplantation is curative for patients with unresectable primary hepatic paraganglioma. For locally advanced unresectable hepatic paraganglioma that involves the intrapericardial vena cava, a meticulous pre- and intraoperative medical management and transabdominal intrapericardial vascular control of the suprahepatic vena cava during orthotopic liver transplantation allows for complete extirpation of the tumor and achieves optimal outcome.

Weaning of Veno-venous Bypass in Liver Transplantation: A Single Center Experience.

BACKGROUND: Veno-venous bypass (VVB) has been used in liver transplantation (LT) to minimize hemodynamic instability during caval anastomosis of anhepatic phase. With the introduction of the piggyback (PB) technique, which is a caval-sparing technique, the use of VVB progressively decreased over the world. The aim of this study was to introduce our experience using VVB with the focus on its weaning process. METHODS: A total of 300 consecutive LT cases from May 1996 to November 2003 were examined. Except for pediatric LT, 242 LT cases were investigated to evaluate the trends in VVB use, surgical technique, the amount of transfusion requirements, and durations of operation and anhepatic phase. RESULTS: For the early 100 LT cases, VVB was used in 97.5% of recipients, especially in all the recipients of deceased donor LT (DDLT). Then, the frequency of VVB use was decreased, and VVB was not used after the 268th recipient. In DDLT, the PB technique was first introduced in the 58th recipient and became a routine procedure of the DDLT since the 191th recipient. Living donor LT was increased, and the amount of transfusion requirement, duration of operation, and duration of anhepatic phase was reduced over time. CONCLUSIONS: The increasing experience and sophisticated surgical and anesthetic techniques were important factors responsible for the weaning of VVB. The advancement of the PB technique used in living donor LT might be a main factor of its weaning.

The Mouse Aortocaval Fistula Model with Intraluminal Drug Delivery.

The arteriovenous fistula (AVF) is the most common type of vascular access currently used for hemodialysis, but long-term outcomes remain poor in many patients; understanding the basic mechanisms of venous remodeling within the fistula environment is critical to improve our understanding of AVF maturation. In this chapter, we describe a method to create a murine aortocaval fistula that allows intraluminal drug delivery. This model reliably recapitulates human AVF maturation and therefore is a good consideration to study venous remodeling.

Transcaval approach for endovascular aortic interventions: A systematic review.

The caval-aortic path is a novel access route for endovascular aortic interventions in aortic interventions, particularly for patients unsuitable for traditional access routes including femoral, subclavian, transapical, and aortic. A systematic review was conducted as per the PRISMA guidelines utilizing three electronic databases: Medline, Embase, and Cochrane database. There were 10 studies identified, including 7 retrospective studies, 1 prospective cohort study, and 2 case reports. Data on 209 patients (mean age 79.5±5.1 years; 51.2% male) were abstracted including preoperative work-up, technical procedure details, and outcomes. The overall technical success rate for all procedures is 96.2%, with a 4.3% mortality rate and a mean follow up of 17.9±19.8 months. Individually in the various interventions, the technical success rate of transcaval endoleak repair and transcatheter aortic valve implantation (TAVI) was 94.4% and 97.5% respectively, with a low 30-day mortality rate of 7.6% in the TAVI intervention. There is encouraging evidence regarding the rates of mortality and complications in the transcaval approach for endovascular aortic interventions. It presents a feasible alternative for a judiciously select group of patients who are not suitable for other access routes.

Impact of Flow Differentials According to Cardiac and Respiratory Cycles on Three Types of Fontan Operation.

Few hemodynamic comparison studies on various types of Fontan operation have been reported. The objective of this study was to perform hemodynamic comparisons for flow size and volume in three types of Fontan operation: atriopulmonary connection (APC), lateral tunnel (LT), and extracardiac conduit (ECC). Forty patients with Fontan operation (8 with APC Fontan, 22 with LT Fontan, and 10 with ECC Fontan) were enrolled. Velocity time integral (VTI) and average peak velocity (APV) were assessed according to cardiac and respiratory cycles in SVC, IVC, hepatic vein, conduit, LPA, and RPA using direct intravenous Doppler echocardiography. During each cardiac cycle in APC, VTI and APV between inspiration and expiration did not show significant differences in SVC, IVC, HV, LPA, or RPA. During each cardiac cycle in LT and ECC, VTI and APV between inspiration and expiration showed significant differences in all native vessels. The gap between S and D wave in APC was the highest, followed by that in LT. It was the lowest in ECC regardless of inspiration or expiration. Hepatic reverse VTI and APV in APC showed significant decreases compared to those in VC and PA during inspiration and expiration. Flow size and volume in APC were more influenced by cardiac cycle. Those in LT were moderately influenced by both respiratory cycle and cardiac cycle while those in ECC were more influenced by respiratory cycle. APC Fontan has hemodynamic inefficiency with prominent reverse flow. However, total cavopulmonary connection (TCPC) Fontan has more hemodynamic efficiency without prominent reverse flows.

Transcaval Valve-in-Valve-in-Valve Aortic Valve Replacement for Bioprosthetic Valve Degeneration.

A 74-year-old man presented with progressive dyspnea on exertion. History included peripheral arterial disease and coronary artery bypass grafting with aortic valve replacement 12 years ago. Subsequently, the surgical valve developed severe stenosis and moderate insufficiency. He underwent a transapical valve-in-valve transcatheter aortic valve replacement 5 years before presentation. This second valve developed a mean gradient of 66 mm Hg with mild insufficiency. The patient was treated with a third aortic valve using an alternative transcaval approach, significantly alleviating his symptoms.